Messages in this thread | | | Date | Mon, 17 Aug 2009 12:45:45 +1000 (EST) | From | James Morris <> | Subject | Re: Security: information leaks in /proc enable keystroke recovery |
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On Sun, 16 Aug 2009, Theodore Tso wrote:
> On Mon, Aug 17, 2009 at 12:31:38AM +0000, David Wagner wrote: > > > > OK. What about this: > > > > (a) Remove ESP and EIP from /proc/$pid/stat{,us} entirely. Put them in > > some other file that is only readable by root and by the owner of the > > process, but is not world-readable. We know that ESP and EIP can be used > > for keystroke recovery, and they are not usually used by administrators, > > so the first step is to lock them down tightly: there is no downside. > > Agreed.
It might be best to require a capability for this if not root.
The candidates seem to be CAP_SYS_ADMIN and CAP_SYS_PTRACE.
> Maybe we should only be recording the last access and last modified > time on pseudo-tty's to a second granularity, hmmm?
I can't think of a valid case for finer granularity here, although I guess it could be made a sysctl if necessary.
I wonder if there are any other channels?
- James -- James Morris <jmorris@namei.org>
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